1. FIELD OF THE INVENTION
The present invention relates generally to internal combustion engines and more particularly to a particular piston and enclosing cylinder construction for internal combustion engines. The present invention specifically relates to a rotary valve head assembly and related drive system for internal combustion engines.
2. DESCRIPTION OF THE PRIOR ART
Rotary valve configurations are well known in prior art and are used in various forms in internal combustion engines. Rotary valves are favored over poppet valve arrangements because they have a potential for unobstructed flow, providing intake and exhaust efficiencies which exceed those of the most sophisticated multi-valve poppet arrangements.
An example of a rotary valve configuration is set forth U.S. Pat. No. 1,118,975 issued Dec. 1, 1914 to Horrace Russ Van Vleck. This configuration includes a casing having a bore on both the intake side and the exhaust side. The intake bore is provided with an inlet valve comprising two valve members. One of these valve members is a sleeve which fits snugly in the intake bore and rotates freely therein. The other valve member fits snugly in the sleeve and rotates freely therein. In the exhaust bore is provided an exhaust valve. The three rotary valve members are connected by a suitable gear arrangement to the crankshaft. In accordance with this gear arrangement, the intake sleeve and the exhaust valve are rotated at one-quarter the speed of the crank shaft and the intake valve is rotated at three-quarters the speed of the crank shaft. This effects sufficient intake passage for ample supply of gas and permits the intake passage to remain open through a substantial portion of the downward stroke of the piston. To ensure proper lubrication of the intake valve sleeve and valve, the sleeve is provided with radial openings therethrough to permit passage of lubricant to the valve; the valve is further provided with depressions therein to receive and hold and aid in distributing a lubricant over the surface of the valve.
U.S. Pat. No. 1,213,873 issued Jan. 30, 1917 to George E. Hollmann shows and describes another rotary valve configuration. This rotary valve configuration includes tubular valve casings and tubular valve sleeves that fit within the valve casings. Each casing has a chambered core extending therethrough which affords a bearing for a corresponding valve sleeve. The core has two chambers, one serving as a space for cooling water, and the other for conducting combustible mixture. The valves have a running fit between corresponding valve casings and cores, having ports which open corresponding cylinder ports when registered therewith. Each valve extends at one end beyond its casing and has fixed thereon a gear wheel that meshes with a driving gear. The driving gear is driven by the crankshaft.
Another rotary valve configuration is provided in U.S. Pat. No. 1,286,967 issued Dec. 10, 1918 to Henry Eschwei. This configuration includes a casting having longitudinally disposed bores within which rotatable valves are positioned. The valves are provided with spiral grooves for carrying lubricants which lubricate the exterior surface of the valve. The valves are driven by a worm wheel arrangement connected to a vertical shaft which is in turn connected to the crankshaft via a beveled gear arrangement.
U.S. Pat. No. 5,205,251 issued Apr. 27, 1993 to Ronald J. Conklin Yet provides yet another rotary valve. This rotary valve comprises a cylindrical valve body rotatably displaceable within a valve sleeve. The valve sleeve is rotatably disposed within the head of an internal combustion engine. Both intake and exhaust functions have a rotary valve. Under normal operations, the valve sleeves and body rotate at the same speed, opening intake and exhaust ports at appropriate times. Advancing or retarding valve timing is accomplished by varying the rotational velocity of either the valve body or the valve sleeve which in turn rotates the valve sleeve relative to the valve body to either advance or retard the appropriate port.
Still another rotary valve arrangement is set forth in U.S. Pat. No. 5,372,104 issued Dec. 13, 1994 to Bill E. Griffin. This arrangement employs valve body rotatably disposed within a valve sleeve. Sealing members and rings inset into a valve rotor and which encircle the valve rotor. Only the sealing members and rings contact the inner surface of the valve sleeve and thus prevent the valve rotor from contacting the valve sleeve. The sealing members are spring biased to ensure that the sealing members maintain contact with the inner surface of the valve sleeve.
The present invention is distinguished from the aforementioned rotary valve configurations in that it is not comprised of two valve members but rather is a single valve spool, that is, it does not employ a valve sleeve. Moreover, the instant invention provides a valve drive assembly which permits advancing or retarding intake and exhaust valves independently, something which cannot be accomplished by inventions of the prior art. It should also be noted that the instant invention does not have sealing members or rings inset in the valve spool.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.